1. Field of the Invention
This invention pertains generally to the field of vehicle display units that present navigation information to the user of a vehicle such as the pilot of an aircraft.
2. Description of the Related Art
Terrain formats on aircraft flight displays based upon traditional enhanced ground proximity warning systems typically depict a two-dimensional representation of local ground terrain for the purpose of navigation around potential terrain threats. By comparison, a Synthetic Vision System (“SVS”) may provide a three-dimensional, perspective view of a scene outside the aircraft, providing graphical imagery for geographic and man-made features such as terrain, obstacles, and runways in the immediate vicinity of the aircraft.
The topographical map and the SVS depictions of the local terrain, however, may appear quite dissimilar because one may be a two-dimensional “plan” view (i.e., looking down at the local terrain) and the other may be a three-dimensional “egocentric” view. As such, this may make the pilot mentally correlate information from one depiction with the information presented in the other depiction. For example, terrain features (or other features) that are located in one image may not be readily identifiable in a second image. As a result, the pilot could be easily confused and lose situational awareness when trying to identify the same location in two dissimilar images.